An animal model of respiratory hypersensitivity to industrial chemicals has been developed using guinea pigs. Repeated exposure of animals to antigen aerosols, containing hapten-protein conjugates, results in pulmonary sensitization and antibody production to the haptenic portion of the antigens. Using this procedure, sensitivity to both aliphatic and aromatic chemicals has been achieved. Proposed research will be directed toward inducing pulmonary sensitization in guinea pigs by repeated exposure to vapors of industrial chemicals, i.e., the haptens alone. Sensitization will be assessed by: increased respiratory rate, bronchial constriction, specific antibody formation. If successful, chemicals known to have allergenic abilities in man will be used for animal sensitization. In this way the allergenic potencies of various industrial chemicals can be evaluated in the guinea pig and compared to their reported potencies in man. Such comparisons will enable assessment of the value of the guinea pig as an animal model for pulmonary sensitization of man. Research will also focus on use of hapten-protein conjugates to detect hapten-specific IgE antibodies in sensitized industrial workers. To date, antigens formed by reaction of p-tolyl isocyanate with human serum albumin have been very effective in detecting antibodies to TDI. Evaluation of sera from additional workers will indicate the potential applicability of such serologic tests for pre-employment screening of industrial workers.